This is the first in a two-part series on greenhouse gas emissions from the aviation industry. Part two will run next week.

July 13, 2018, was a day for the books. The Swedish company FlightRadar24 had just tracked 205,468 flights around the world – aviation’s busiest day in history. Determining the carbon footprint of all those flights would have been a herculean task, but a basic back-of-the-envelope calculation yields some jaw-dropping figures.

Consider that even a one-way short-haul flight in Canada (such as the one-hour trip between Ottawa and Toronto) generates about 4,718 kilograms of carbon dioxide (CO2) – about as much as a typical car emits in a year.

If this flight is representative of the global average (for factors like distance travelled, aircraft type and occupancy) then the flights on July 13 would have required the equivalent of over 2.2 million barrels of oil. To be clear, that’s enough energy to power nearly 105,000 North American homes for a whole year. Even more alarming is that it would require 365 days and 1.1 million acres of forest to remove all of that CO2 from the atmosphere.

Since small, non-commercial aircraft are sometimes included in this count, it’s possible that these numbers are an overestimation. Still, even if the estimate is cut in half, the amount of energy burned on that single day of airline travel would be equivalent to every drop of oil extracted from North Dakota’s Bakken oil fields every day.

Business as usual

Somehow, at a time when oil companies and, more recently, livestock producers are berated for their contributions to climate change, the world’s biggest airlines seemed to have largely escaped criticism.

Along with carbon offsets, these innovations can give the false impression that aviation emissions are under control.

Flight emissions account for about two percent of all anthropogenic emissions of CO2 globally, but planes are also responsible for emitting nitrous oxides, water vapour, sulfates and soot, all of which impact the climate. The Intergovernmental Panel on Climate Change (IPCC) found that in 1992, aviation was responsible for 3.5 percent of all human-caused climate change; they estimated that number would climb to five percent by 2050. But that figure doesn’t account for aviation’s lengthy supply chain, which, if properly factored in, would have to include all the energy that’s used to build, maintain and power everything from airports and runways to energy used in producing, refining, storing and transporting jet fuel.

Accurate estimates of global emissions for the entire aviation supply chain are hard to find, but one U.S.-focused study from 2008 found that 30 percent of aircraft emissions are generated through indirect emissions – actions like fuel production, aircraft manufacturing and airport and runway construction. If the same is true in global terms, then the aviation sector is responsible for about 4.6 percent of human-caused climate change.

(For perspective, the global livestock industry – everything from direct animal emissions to indirect emissions from the supply chain – accounts for 14.5 percent of worldwide GHG emissions. That said, roughly 6 percent of the planet’s population flies on any given day, compared to 95 percent of people who eat meat.)

While it’s true the public is gaining an increased understanding that flying contributes to climate change, there is little awareness of how significantly it contributes to it. And more worryingly, there seems to be little focus on the impacts it could have if air travel continues unabated, as many, including the International Air Transport Association (IATA), suspect will happen. Indeed the IATA expects air travel will double over the next two decades alone.

Given the undeniable risks of climate change, how does the aviation industry maintain its business-as-usual operations without being asked to further curb its emissions?

It’s all about perception

Although there have been technological innovations and efficiency gains in aviation, there is a perception that the corporations building and operating aircrafts, and the governments regulating them, are doing all they can to tackle climate change.

If this flight is representative of the global average then the flights on July 13 would have required the equivalent of over 2.2 million barrels of oil.

This perception doesn’t match the reality. Electric airplanes, for example, do exist, but they aren’t yet ready for commercial use. Still, the growing prevalence of innovative solutions like biofuels, newer, lightweight materials and improvements in air traffic management (all of which reduce emissions) are a step in the right direction. And along with carbon offsets, these innovations can give the false impression that aviation emissions are under control.

Nothing could be further from the truth. The sector’s target of 1.5 percent fuel efficiency improvements per year between 2009 and 2020 mean little when the industry is overwhelmed by the annual growth in passengers. Since 2009 when the efficiency target was agreed to, the growth in passenger demand has hovered around 6 percent per year, meaning improvements in efficiency are useful, but they’re not enough to match ever-climbing emissions.

Ryan M. Katz-Rosene is an Assistant Professor at the University of Ottawa's School of Political Studies, and serves as Co-President of the Environmental Studies Association of Canada. He lives on an organic farm near Wakefield, Quebec.